Confetti is an excellent study of what happens when someone botches Christopher Guest's mockumentary format. A supposed satire of extravagant weddings and reality shows, Debbie Isitt's feature displays little in the way of wit or insight. It's long and tedious, and amusing only on rare, widely spaced occasions. Unlike Guest's films, which show affection for the people being mocked, Isitt treats her cast of mostly unlikable characters with contempt, then attempts to redeem them with third-act character-building scenes that are steeped in melodrama.

The saving grace of Confetti, to the extent that there can be said to be one, is the acting. With the possible exception of Martin Freeman, who was Arthur Dent in 2005's big-screen The Hitchhiker's Guide to the Galaxy, the cast is comprised predominantly unknown performers. They all do fine jobs, selling us characters that are done a disservice by an uneven script. Special kudos is deserved by Robert Webb and Olivia Colman, who are fully nude in about half of their scenes.

The premise sounds tailor-made for a mockumentary, so the problems are in the execution. Confetti magazine is running a contest to see who can stage Britain's most unusual wedding. The winning couple will get a new house. There are three finalists, and the film follows them down the rocky road to the happy day. There are Matt (Martin Freeman) and Sam (Jessica Stevenson), who want a wedding with a Hollywood musical theme. Tennis buffs Josef (Stephen Mangan) and Isabelle (Meredith MacNeill) want to incorporate their passion into the ceremony. Nudists Michael (Robert Webb) and Joanna (Olivia Colman) want to the proceedings to be clothing optional. The magazine recruits wedding planners Archie (Vincent Franklin) and Gregory (Jason Watkins) to supervise things, but they quickly realize they are out of their depth.

Confetti is one of those Murphy's Law motion pictures where everything that can go wrong, does go wrong, before being sorted out to facilitate a reasonably happy ending. Yet the movie manages to take potentially madcap situations and drain them of humor. Confetti offers occasional, half-hearted chuckles, but there isn't even a single moment of explosive or inspired comedy. There are the usual gay jokes, gags about naked people, and problematic in-law situations. Everything in the movie is expected, from Matt's confrontation with Sam's bitter mother to Michael and Joanna's decision to defy the nudity ban at their naked wedding. When married with cleverness, predictability isn't necessarily a bad thing, but Confetti has the former while mostly lacking the latter.

Perhaps Isitt's biggest mistake is to do an about-face midway through the movie and attempt to inject some drama. The movie's satirical structure, failed though it may be, doesn't support this. Her attitude toward the characters during the first half wavers between scorn and condescension, then she suddenly changes her mind and expects us to care what happens to them. Not only does it not work, but it underscores Confetti's artificiality. Her big points appear to be that the wedding process has gotten out of hand and that reality shows are stupid. It would be hard to find two more obvious statements, and we don't need a movie - especially this movie - to confirm them.